A basic filter change on a regular basis can have a significant impact on engine life and performance. It doesn't take long, saves you money, and sends your car down the road refreshed and renewed. A clogged air filter can cause poor performance and reduced engine life. This simple procedure guards against that and should be done every 12 months or 12,00 miles. According to Edmunds.com here is the step-by-step process to change your air filter.
Then, park your car in the shade and pop the hood. Prop it up so it doesn't bang you in the head, then let the engine cool for a few minutes. While it's cooling, go get your tools. You'll need very few for this procedure — grab a butter knife, two medium-sized screwdrivers, one standard and one Phillips.
The air filter is typically enclosed in a black plastic casing near the center-top of the engine (sometimes, however, it will be off to the side). It should be the largest non-metal assembly you see, about the size of a breadbox. Now, open it.
Since it is usually held together by a couple of large metal clips on the side, slide the butter knife or flat-headed screwdriver between the casing and the clip and then pry the clip away. Continue around the case's perimeter, loosening all the retaining clips which should allow you to open the case up. Occasionally you'll find an air filter housing that's held together with several long screws, in which case you'll have to unscrew them to get at the filter. You'll find the air filter inside. It's usually white, bright yellow, orange or red, the better to see the collected dirt.
Pull out the filter — it's typically flat and/or elongated but some vehicles have oval air filters, it's made of a paper element with rubber edges to seal it against the casing.
Next, check it for cleanliness. Hold it up to the sunlight and (while keeping it at arm's length from your face) bend it back, so the paper ridges of the filter flutter like the pages of a book, and look inside the crevices. Do you see a lot of accumulated dirt and grime? Now look at it straight on. Is the orange or yellow paper mostly dirty in the center? If so, then you should replace it.
Close up the casing and put the old air filter in a plastic grocery bag. Place the new filter in, seal it up and you're done.